Stretchable display with fixed pixel density

ABSTRACT

The present disclosure is directed to systems and methods of forming an expandable display device capable of maintaining a fixed pixel density at any display area from a relatively smaller first display area to a relatively larger second display area. The expandable display device includes an upper display layer and a lower display layer. In a first display position, the display elements having a defined pixel density included in the upper display layer obscure the display elements included in the lower display layer. The upper display layer and lower display layers are disposed on expandable substrates capable of continuous displacement between the first and second display positions. In the second display position, the display elements included in the lower display layer are visible through gaps between the display elements included in the upper display layer. The resultant display provides a uniform pixel density at all displacements between the first and second display positions.

TECHNICAL FIELD

The present disclosure relates to display devices, more specifically todisplay devices featuring a variable display area.

BACKGROUND

Electronic devices are, with greater frequency, expected to increase incomputational versatility while maintaining as small a form factor aspossible. Unfortunately, the size limitations imposed by small formfactor design, often result in a compromised fixed format display size.As the versatility of portable devices increases, the relatively smalldisplay size serves to functionally limit the usefulness (andconsequently, acceptance) of small form factor devices.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of various embodiments of the claimed subjectmatter will become apparent as the following Detailed Descriptionproceeds, and upon reference to the Drawings, wherein like numeralsdesignate like parts, and in which:

FIG. 1A is a plan view of an illustrative expandable display devicedepicting an illustrative upper layer incorporating a plurality of upperdisplay elements disposed on an upper expandable substrate, inaccordance with at least one embodiment described herein;

FIG. 1B is a plan view of the illustrative expandable display devicedepicting an illustrative lower layer incorporating a plurality of lowerdisplay elements disposed on a lower expandable substrate, in accordancewith at least one embodiment described herein;

FIG. 1C is a plan view of the illustrative expandable display devicedepicting the upper layer shown in FIG. 1A stacked above the lower layershown in FIG. 1B after the application of a force applied along twoorthogonal axes, in accordance with at least one embodiment describedherein;

FIG. 2A is a plan view of an illustrative expandable display devicehaving a first display area that includes 6×6 upper display elementmatrix, in accordance with at least one embodiment described herein;

FIG. 2B is a partial cross-sectional view of the illustrative expandabledisplay device depicted in FIG. 2A, along sectional line 2B-2B, inaccordance with at least one embodiment described herein;

FIG. 2C is a plan view of the illustrative expandable display device ina stretched or expanded state to provide the second display area inwhich both the upper layer that includes 36 upper display elements andthe lower layer that include 25 lower display elements are both visible,in accordance with at least one embodiment described herein;

FIG. 2D is a partial cross-sectional view of the illustrative expandabledisplay device depicted in FIG. 2C, along sectional line 2D-2D, inaccordance with at least one embodiment described herein;

FIG. 3A is a cross-sectional elevation of another illustrative upperdisplay element that includes a rigid substrate, in accordance with atleast one embodiment described herein;

FIG. 3B is a cross-sectional elevation of another illustrative lowerdisplay element that includes a rigid substrate, in accordance with atleast one embodiment described herein;

FIG. 4 is a plan view of an illustrative system that includes twodisplay elements conductively coupled using a flexible interconnect, inaccordance with at least one embodiment described herein;

FIG. 5 is a schematic diagram of an illustrative electronic,processor-based, device that includes processor circuitry and a graphicsprocessing unit coupled to an expandable display device such asdescribed in detail with regard to FIGS. 1-4, in accordance with atleast one embodiment described herein;

FIG. 6 is a plan view of an illustrative expandable display system thatincludes an upper display layer and an lower display layer that areshown separated, in accordance with at least one embodiment describedherein;

FIG. 7A is an elevation depicting the detachable attachment ordetachable affixing of an illustrative upper surface of a displayelement to an illustrative first rigid carrier member, in accordancewith at least one embodiment described herein;

FIG. 7B is an elevation depicting the deposition of an adhesive on,about, or across all or a portion of the lower surface of the displayelement, in accordance with at least one embodiment described herein;

FIG. 7C is an elevation depicting the detachable attachment ordetachable affixing of a pre-strained (i.e., extended or displaced tothe second display position) expandable substrate to an illustrativesecond rigid carrier member, in accordance with at least one embodimentdescribed herein;

FIG. 7D is an elevation depicting the attachment or affixing of the backside of the display element to the pre-strained (i.e., extended ordisplaced to the second display position) expandable substrate, inaccordance with at least one embodiment described herein;

FIG. 7E is a plan view of an illustrative upper layer that includes aplurality of display elements disposed across all or a portion of thepre-strained expandable substrate and an illustrative lower layer thatincludes a plurality of display elements disposed across all or aportion of the pre-strained expandable substrate, in accordance with atleast one embodiment described herein;

FIG. 7F is an elevation depicting an expandable display device havingthe upper layer stacked on the lower layer and separated by spacermember, in accordance with at least one embodiment described herein;

FIG. 7G is an elevation depicting the expandable display device in whichthe expandable substrate has been released and the expandable displaydevice returns to the first display position having width, in accordancewith at least one embodiment described herein;

FIG. 8 is a high-level flow diagram depicting an illustrative expandabledisplay device manufacturing method, in accordance with at least oneembodiment described herein; and

FIG. 9 is a high level logic flow diagram of an illustrative method forproviding a display image on an expandable display device such asdescribed above in FIGS. 1 through 6 while maintaining a fixed pixeldensity in the display image, in accordance with at least one embodimentdescribed herein.

Although the following Detailed Description will proceed with referencebeing made to illustrative embodiments, many alternatives, modificationsand variations thereof will be apparent to those skilled in the art.

DETAILED DESCRIPTION

The systems and methods described herein advantageously provide anexpandable or stretchable display device capable of displacement along asingle axis or along multiple axes while beneficially retaining a fixedpixel density. Thus, the systems and methods described herein overcomethe reduced resolution of prior expandable or stretchable displaydevices. The ability to maintain a fixed pixel density as a displaydevice continuously transitions from a first display position to asecond display position represents a significant advantage, particularlywhen executing an application that benefits from high resolutiongraphics.

The systems and methods described herein include a display device havinga positionable, expandable, and continuously displaceable upper layerpositioned above a positionable, expandable, and continuouslydisplaceable lower layer. The upper layer includes a first plurality ofdisplay elements affixed to an expandable or stretchable substrate. Eachof the display elements included in the first plurality of displayelements has a defined physical geometry that includes a matrix formedusing any number of pixels. The lower layer includes a second pluralityof display elements affixed to an expandable or stretchable substrate.Each of the display elements included in the second plurality of displayelements has a defined physical geometry that includes a matrix formedusing any number of pixels.

The each of the first plurality of display elements are conductivelycoupled to at least one other of the display elements in the firstplurality of display elements. Similarly, each of the second pluralityof display elements are conductively coupled to at least one other ofthe display elements in the second plurality of display elements. As thedisplay device is expanded or stretched, the display elements includedin the first plurality of display elements separate, revealing anincreasing portion of each of the display elements included in theunderlying second plurality of display elements. Beneficially, the pixeldensity of the display remains constant at any point from a firstposition where the display elements included in the second plurality ofdisplay elements are obscured to a second position where the displayelements included in the second plurality of display elements arecompletely exposed.

By way of illustrative example—assume the upper layer includes four 1 cmby 1 cm square display elements, each measuring 6 pixels by 6 pixels—theupper layer thus forms a 2 cm by 2 cm, 12 pixel by 12 pixel, displayarea; the lower layer also includes four 1 cm by 1 cm square displayelements, each measuring 6 pixels by 6 pixels (6 pixels/cm)—the lowerlayer thus forms a 2 cm by 2 cm, 12 pixel by 12 pixel, display area thatis disposed beneath the upper layer. As the display is stretched, aportion of each of the display elements on the lower layer are exposed.Control circuitry monitors the position of the upper display elementsand the lower display elements to maintain image continuity as thedisplay is expanded or stretched. When fully stretched along both thex-axis and the y-axis, the display elements on the lower layer arecompletely exposed. When fully stretched, the display measures 4 cm by 4cm and has a resolution of 24 pixels by 24 pixels (6 pixels/cm).Advantageously, using the systems and methods described herein, thepixel density (and consequently, image quality) remains consistentcontinuously throughout the expansion process.

A variable viewing area display device continuously displaceable betweena first display position that provides a first display area and a seconddisplay position that provides a second display area, the second displayarea larger than the first display area is provided. The display devicemay include: an upper display layer that includes a plurality of upperdisplay elements disposed on an expandable substrate, the expandablesubstrate continuously displaceable between the first display positionand the second display position; a lower display layer that includes aplurality of lower display elements disposed on an expandable substrate,the expandable substrate continuously displaceable between the firstdisplay position and the second display position wherein: in the firstdisplay position the plurality of upper display elements obscure atleast a portion of the plurality of lower display elements; as thedisplay device is displaced from the first position to the secondposition, at least a portion of each of the plurality of lower displayelements are visible through void spaces formed in the expandablesubstrate of the upper display layer between each of at least some ofthe plurality of upper display elements; and in the second position eachof the plurality of lower display elements are visible through the voidspaces formed in the expandable substrate of the upper display layerbetween each of at least some of the plurality of upper displayelements.

A variable area display method is provided. The method may include:receiving, by expandable display control circuitry, a signal thatincludes information indicative of a relative position of an upperdisplay layer with respect to a lower display layer; identifying, by theexpandable display control circuitry, an exposed portion of each of aplurality of lower display elements based on the relative position ofthe upper display layer with respect to the lower display layer;determining, by the expandable display control circuitry, a firstportion of a display image for display using a plurality of upperdisplay elements included in the upper display layer; and determining,by the expandable display control circuitry, a second portion of adisplay image for display using the identified exposed portion of eachof the lower display elements such that a display image having a uniformpixel density is maintained.

Another variable area display method is provided. The method mayinclude: pre-straining an upper expandable substrate having an uppersurface and a lower expandable substrate having an upper surface;affixing a rear surface of each of a plurality of upper display elementsto the upper surface of the upper expandable substrate; each of theplurality of upper display elements spaced apart from at least one otherof the plurality of upper display elements to form interstitial spacesseparating each of the plurality of upper display elements from eachother on the upper expandable substrate; affixing a rear surface each ofa plurality of lower display elements to the upper surface of the lowerexpandable substrate; each of the plurality of lower display elementsspaced apart from at least one other of the plurality of lower displayelements to form interstitial spaces separating each of the plurality oflower display elements from each other on the lower expandablesubstrate; removing portions of the upper expandable substrate in theinterstitial spaces that separate the plurality of upper displayelements; stacking the pre-strained upper expandable substrate on thepre-strained lower expandable substrate; and releasing the strain on theupper expandable substrate and the strain on the lower expandablesubstrate.

Another variable area display system is provided. The system mayinclude: means for receiving a signal that includes informationindicative of a relative position of an upper display layer with respectto a lower display layer; means for identifying an exposed portion ofeach of a plurality of lower display elements based on the relativeposition of the upper display layer with respect to the lower displaylayer; means for determining a first portion of a display image fordisplay using a plurality of upper display elements included in theupper display layer; and means for determining a second portion of adisplay image for display using the identified exposed portion of eachof the lower display elements such that a display image having a uniformpixel density is maintained.

A non-transitory machine-readable storage medium that includesinstructions is provided. The instructions, when executed by expandabledisplay control circuitry, cause the expandable display controlcircuitry to: receive a signal that includes information indicative of arelative position of an upper display layer with respect to a lowerdisplay layer; identify an exposed portion of each of a plurality oflower display elements based on the relative position of the upperdisplay layer with respect to the lower display layer; determine a firstportion of a display image for display using a plurality of upperdisplay elements included in the upper display layer; and determine asecond portion of a display image for display using the identifiedexposed portion of each of the lower display elements such that adisplay image having a uniform pixel density is maintained.

An electronic device is provided. The electronic device may include: aprinted circuit board; processor circuitry; input/output (I/O)circuitry; and a variable viewing area display device continuouslydisplaceable between a first display position that provides a firstdisplay area and a second display position that provides a seconddisplay area, the second display area larger than the first displayarea, the variable viewing area display device comprising: an upperdisplay layer that includes a plurality of upper display elementsdisposed on an expandable substrate, the expandable substratecontinuously displaceable between the first display position and thesecond display position; a lower display layer that includes a pluralityof lower display elements disposed on an expandable substrate, theexpandable substrate continuously displaceable between the first displayposition and the second display position wherein: in the first displayposition the plurality of upper display elements obscure at least aportion of the plurality of lower display elements; as the displaydevice is displaced from the first position to the second position, atleast a portion of each of the plurality of lower display elements arevisible through void spaces formed in the expandable substrate of theupper display layer between each of at least some of the plurality ofupper display elements; and in the second position each of the pluralityof lower display elements are visible through the void spaces formed inthe expandable substrate of the upper display layer between each of atleast some of the plurality of upper display elements.

FIG. 1A is a plan view of an illustrative expandable display device 100depicting an illustrative upper layer 110 incorporating a plurality ofupper display elements 112A-112 n (collectively—“upper display elements112”—four such upper display elements, 112A-112D, are shown in FIG. 1A)disposed on an upper expandable substrate 120, in accordance with atleast one embodiment described herein. As depicted in FIG. 1A, a gap130, with spacing 132, exists between each of the plurality of upperdisplay elements 112. The each of the upper display elements 112 isconductively coupled to a neighboring upper layer display element 112 byone or more conductive couplings 140A-140 n (collectively, “conductivecouplings 140”—four such conductive couplings 140A-140D, are shown inFIG. 1A).

FIG. 1B is a plan view of the illustrative expandable display device 100depicting an illustrative lower layer 150 incorporating a plurality oflower display elements 152A-152 n (collectively—“lower display elements152”—four such lower display elements, 152A-152D, are shown in FIG. 1B)disposed on a lower expandable substrate 160, in accordance with atleast one embodiment described herein. As depicted in FIG. 1B, a gap170, with spacing 172, exists between each of the plurality of lowerdisplay elements 152. The each of the upper display elements 152 isconductively coupled to a neighboring upper layer display element 152 byone or more conductive couplings 180A-180 n (collectively, “conductivecouplings 180”—four such conductive couplings 180A-180D, are shown inFIG. 1B). In embodiments, the upper display elements 112 and the lowerdisplay elements 152 are staggered such that the gaps 130 between upperdisplay elements 112 and the gaps 170 between lower display elements 152are not in vertical alignment and the actual upper display elements 112are not in vertical alignment with the lower display elements 152.

FIG. 1C is a plan view of the illustrative expandable display device 100depicting the upper layer 110 shown in FIG. 1A stacked above the lowerlayer 150 shown in FIG. 1B after the application of a force 190 appliedalong two orthogonal axes 190A and 190B, in accordance with at least oneembodiment described herein. As depicted in FIG. 1C, the upper displayelements 112 may be displaced from a first display position (FIG. 1A—inwhich the lower display elements 152 are partially or completelyobscured) to a second display position (FIG. 1C—in which the upperdisplay elements 112 are spaced apart a second distance 132B in whichthe lower display elements 152 are partially or completely exposed).

In embodiments, the upper display elements 112 includes any number ofpixels arranged in any geometric shape. Thus, although the upper displayelements 112 are depicted as square-shaped in FIG. 1A, in otherembodiments, the upper display elements 112 may have a circular, oval,polygonal, rectangular, or similar geometric shape. Each of the upperdisplay elements may include an upper surface that forms the visibleimage portion of the display device and a rear surface that includesvarious electrical circuits and semiconductor components used toactivate the pixels forming the upper display element 112. Inembodiments, the upper display elements 112 may include a plurality ofred pixels 116R, green pixels 116G, and blue pixels 116B disposed toform a Bayer filter pattern 154. In embodiments, the pixels forming theupper display elements 112 are arranged to form a single or repeatingpattern. In other embodiments, the pixels forming the upper displayelements 112 are distributed randomly or pseudo-randomly across thesurface of the upper layer display element 112. In embodiments, theupper display elements 112 are square shaped and include a pixel matrixthat of 4 pixels high by 4 pixels wide (4 pixels×4 pixels) or higher; 8pixels×8 pixels or higher; 12 pixels by 12 pixels or higher; 16 pixelsby 16 pixels or higher 32 pixels by 32 pixels or higher; 64 pixels by 64pixels or higher; or 128 pixels by 128 pixels or higher. The upperdisplay elements 112 may include any number and/or combination ofcurrently available or future developed active (i.e., emissive) pixeltechnology, including but not limited to: light emitting diodes (LEDs);organic LEDs (OLEDs); polymer LEDs (PLEDs); or combinations thereof.

The upper display elements 112 are disposed in, on, about, or across allor a portion of the expandable substrate 120. The expandable substrate120 may include one or more materials capable of continuous expansionfrom a first display position that provides a first display area to asecond display position that provides a second display area. Theexpandable substrate may include one or more polymers or elastomerscapable of expansion along one axis (e.g., display diagonal, height, orwidth) or expansion along two orthogonal axes (e.g., display deviceheight and width). The interstitial expandable substrate 120 between theupper display elements 112 is removed such that when the expandablesubstrate 120 is displaced from the first display position voids or gapsform in the expandable substrate 120. All or a portion of each of thelower display elements 152 are visible through the voids or gaps as theexpandable substrate 120 is displaced from the first display position tothe second display position. In embodiments, when the upper layer 110 isdisposed in the second display position, each of the plurality of lowerdisplay elements 152 are visible through a gap or void in the expandablesubstrate 120. In embodiments, the expandable substrate 120 is biasedtowards the first display position. In such embodiments, one or moretensioning devices may maintain the expandable substrate 120 in anexpanded position between the first display position and the seconddisplay position.

In embodiments, the expandable substrate 120 has a uniform compositionthroughout and each of the plurality of upper display elements 112 maybe affixed directly to the expandable substrate using one or morebonding systems or methods (adhesive, thermosetting resin, etc.). Inother embodiments, the expandable substrate 120 may be formed orotherwise disposed partially or completely about rigid members (e.g.,rigid “islands” disposed in an expandable or elastomeric material) suchthat application of force 190 causes an elongation of the expandablesubstrate 120 but not the rigid members disposed within the expandablesubstrate 120. In such embodiments, the upper display elements 112 arephysically and/or chemically affixed, bonded, or otherwise attached tothe rigid members disposed in, on, or about the expandable substrate120.

Each of the plurality of upper display elements 112 is spaced apart fromthe remaining upper display elements 112 by gap 130. In the firstdisplay position, the gap 130 between the upper display elements 112 mayhave a first dimension 132A. In the first display position, the void orgap in the expandable substrate 120 may have the first dimension 132A.In the second display position, the gap 130 between the upper displayelements may have a second dimension 132B that is larger than the firstdimension 132A. In the second display position, the void or gap in theexpandable substrate 120 may have the second dimension 132B.

One or more flexible conductors 140 couple each of the plurality ofupper display elements 112 to one or more other of the upper displayelements 112. The flexible conductors 140 include any number ofconductive pathways or traces and may provide communication between eachof the upper display elements 112 and expandable display controlcircuitry 102 that cause the upper display elements 112 and lowerdisplay elements 152 to display a coherent image when the display ispositioned at the first display position, the second display position,or any location between the first display position and the seconddisplay position. In embodiments, the system 100 includes one or moresensors 104 that provide one or more position signals 106 that containinformation and/or data indicative of the position of the upper layer110 with respect to the lower layer 150. The expandable display controlcircuitry 102 uses the information and/or data included in the one ormore position signals 106 to determine the content provided by the upperdisplay elements 112. The expandable display control circuitry 102 usesthe information and/or data included in the one or more position signals106 to determine the percentage of pixels included in the lower displayelements 152 to energize based on the portion of the lower displayelements 152 exposed by the position of the upper layer 110 with respectto the lower layer 150.

The expandable display control circuitry 102 includes any number and/orcombination of currently available and/or future developed electricalcomponents, semiconductor devices, and/or logic elements capable ofdetermining the relative position of the upper layer 110 with respect tothe lower layer 150 and adjusting the display output of the pixelsincluded on the lower display elements 150 to maintain image coherencywith the display device positioned at any point between the firstdisplay position and the second display position. In embodiments, theexpandable display control circuitry 102 may determine the portion ofthe lower display elements 152 exposed by the displacement of the upperlayer 110 and may determine the illumination level and content of thepixels included in the respective lower display elements 152 such thatimage displayed by the display device 100 remains coherent.

The one or more sensors 104 include any number and/or combination ofcurrently available and/or future developed sensing elements, electricalcomponents, and/or semiconductor devices capable of producing the one ormore output signals 106 that include information and/or data indicativeof a position of the upper layer 110 with respect to the lower layer150. Example sensors 104 include, but are not limited to one or more:proximity sensors, ultrasonic sensors, LIDAR sensors, strain sensors,stretch sensors, or combinations thereof.

In embodiments, each of the lower display elements 152 include anynumber of pixels arranged in any geometric shape. In embodiments, thegeometric shape of the lower display elements 152 may be similar to orthe same as the geometric shape of the upper display elements 112. Thus,although the lower display elements 152 are depicted as square-shaped inFIG. 1B, in other embodiments, the lower display elements 152 may have acircular, oval, polygonal, rectangular, or similar geometric shape. Eachof the lower display elements 152 may include an front or upper surfacethat forms the visible image portion of the display device and a rear orlower surface that includes various electrical circuits andsemiconductor components used to activate the pixels forming and/orincluded in the lower layer display element 152. In embodiments, thelower display elements 152 may include a plurality of red pixels 156R, aplurality of green pixels 156G, and a plurality of blue pixels 156Bdisposed to form a Bayer filter pattern 154. In embodiments, the pixelsforming the lower display elements 152 are arranged to form a single orrepeating pattern. In other embodiments, the pixels forming the lowerdisplay elements 152 are distributed randomly or pseudo-randomly acrossthe surface of the lower layer display element 152. In embodiments, eachof the lower display elements 152 are square shaped and include a pixelmatrix that of 4 pixels high by 4 pixels wide (4 pixels×4 pixels) orhigher; 8 pixels×8 pixels or higher; 12 pixels by 12 pixels or higher;16 pixels by 16 pixels or higher 32 pixels by 32 pixels or higher; 64pixels by 64 pixels or higher; or 128 pixels by 128 pixels or higher.The lower display elements 152 may include any number and/or combinationof currently available or future developed active (i.e., emissive) pixeltechnology, including but not limited to: light emitting diodes (LEDs);organic LEDs (OLEDs); polymer LEDs (PLEDs); or combinations thereof.

The lower display elements 152 are disposed in, on, about, or across allor a portion of the expandable substrate 160. The expandable substrate160 may include one or more materials capable of continuous expansionfrom a first display position that provides a first display area to asecond display position that provides a second display area. Theexpandable substrate 160 may include one or more polymers or elastomerscapable of expansion along one axis (e.g., display diagonal, height, orwidth) or expansion along two orthogonal axes (e.g., display deviceheight and width). All or a portion of each of the lower displayelements 152 are visible through the voids or gaps as the expandablesubstrate 120 is displaced from the first display position to the seconddisplay position. In embodiments, when the upper layer 110 is disposedin the second display position, at least a portion of each of theplurality of lower display elements 152 are visible through a gap orvoid in the expandable substrate 120 supporting the upper layer 110. Inembodiments, the expandable substrate 160 is biased towards the firstdisplay position. In such embodiments, one or more tensioning devicesmay maintain the expandable substrate 160 in an expanded positionbetween the first display position and the second display position.

In embodiments, the expandable substrate 160 has a uniform compositionthroughout and each of the plurality of lower display elements 152 maybe affixed directly to the expandable substrate 160 using one or morebonding systems or methods (adhesive, thermosetting resin, etc.). Inother embodiments, the expandable substrate 160 may be formed orotherwise disposed partially or completely about rigid members (e.g.,rigid “islands” disposed in an expandable or elastomeric material) suchthat application of force 190 causes an elongation of the expandablesubstrate 160 but not the rigid members supporting the lower displayelements 152 disposed within the expandable substrate 160. In suchembodiments, the lower display elements 152 are physically and/orchemically affixed, bonded, or otherwise attached to the rigid membersdisposed in, on, or about the expandable substrate 160. Each of theplurality of lower display elements 152 is spaced apart from theremaining lower display elements 152 by gap 170. In the first displayposition, the gap 170 between the lower display elements 152 may have afirst dimension 172A.

One or more flexible conductors 180 couple each of the plurality oflower display elements 152 to one or more other of the other lowerdisplay elements 152. The flexible conductors 180 include any number ofconductive pathways or traces and may provide communication between eachof the lower display elements 152 and expandable display controlcircuitry 102 that cause the lower display elements 152 and upperdisplay elements 112 to display a coherent image when the display ispositioned at the first display position, the second display position,or any location between the first display position and the seconddisplay position. In embodiments, the system 100 includes one or moresensors 104 that provide one or more position signals 106 that containinformation and/or data indicative of the position of the upper layer110 with respect to the lower layer 150. The expandable display controlcircuitry 102 uses the information and/or data included in the one ormore position signals 106 to determine the content provided by the upperdisplay elements 112. The expandable display control circuitry 102 usesthe information and/or data included in the one or more position signals106 to determine the percentage of pixels included in the lower displayelements 152 to energize based on the portion of the lower displayelements 152 exposed by the position of the upper layer 110 with respectto the lower layer 150. Beneficially, the display device 100 maintains aconstant pixel density throughout the range of display area from thefirst display area to the second display area.

In operation, in the first display position, the upper display elements112 provide a relative small display area having a defined pixeldensity. For example, in the first display position, the upper displayelements 112 may provide a display device having a pixel density of:greater than about 50 pixels per inch (ppi); greater than about 100 ppi;greater than about 200 ppi; greater than about 300 ppi; greater thanabout 400 ppi; or greater than about 500 ppi. In the second displayposition the upper display elements 112 are displaced a distancesufficient to expose some or all of the lower display elements 152yielding a display device 100 in which both the upper display elements112 and the lower display elements 152 are visible. When in the seconddisplay position, the combined upper display elements 112 and lowerdisplay elements 152 provide a relatively large display area having thesame defined pixel density as the relatively smaller display areaprovided by the upper display elements 112 alone. Thus, in the seconddisplay position, the upper display elements 112 may provide a displaydevice having a pixel density of: greater than about 50 ppi; greaterthan about 100 ppi; greater than about 200 ppi; greater than about 300ppi; greater than about 400 ppi; or greater than about 500 ppi.

FIG. 2A is a plan view of an illustrative expandable display device 200having a first display area that includes 6×6 upper display element 112matrix, in accordance with at least one embodiment described herein. Asdepicted in FIG. 2A, the expandable display device 200 provides a firstdisplay area of width 210 by width 220. FIG. 2B is a partialcross-sectional view of the illustrative expandable display device 200depicted in FIG. 2A, along sectional line 2B-2B, in accordance with atleast one embodiment described herein. FIG. 2C is a plan view of theillustrative expandable display device 200 in a stretched or expandedstate to provide the second display area in which both the upper layer110 that includes 36 upper display elements 112 and the lower layer 150that include 25 lower display elements 152 are both visible, inaccordance with at least one embodiment described herein. As depicted inFIG. 2C, the expandable display device 200 provides a second displayarea of width 270 by height 280. FIG. 2D is a partial cross-sectionalview of the illustrative expandable display device 200 depicted in FIG.2C, along sectional line 2D-2D, in accordance with at least oneembodiment described herein.

As depicted in FIG. 2A, when the expandable display device 200 ispositioned in the first display position, only the upper displayelements 112A-112 n are visible to the system user. The lower displayelements 152A-152 n remain positioned beneath and obscured by the upperdisplay elements 112A-112 n. In the first display position, the one ormore sensors 104 provide to the expandable display control circuitry 102one or more position signals 106 that contain information and/or dataindicative of the position of the upper layer 110 with respect to thelower layer 150. In response, since the lower display elements 152 areobscured, the expandable display control circuitry 102 may cause thedisplay of an image using only the upper display elements 112, allowingthe lower display elements 152 to remain inactivated and notilluminated. In the first display position that provides a displayhaving a first display area having width 210 and height 220, a gap 130having a width of less than: about 0.1 millimeters (mm); about 0.5 mm;about 1.0 mm; about 2 mm; or about 5 mm separates the upper displayelements 112.

In embodiments, each of the upper display elements 112 includes a pixelmatrix in the form of a rectangular or square display element having thesame or different widths 212A-212 n (collectively, “upper displayelement widths 212”) and/or the same or different heights 222A-222 n(collectively, upper display element heights 222″). For example, each ofthe upper display elements 112 may have a length 212 of: about: 0.5centimeters (cm) or less; about 1 cm or less; or about 2 cm or less anda height of: about: 0.5 centimeters (cm) or less; about 1 cm or less; orabout 2 cm or less. Thus, in the first display position, the expandabledisplay device 200 may have a first display area of from about 3 cm by 3cm to about 24 cm by 24 cm. Although a 6×6 matrix of upper displayelements 112 is shown in FIG. 2A, the first display area may include anynumber of upper display elements 112.

Referring next to FIG. 2B, the relative positions of the upper displayelements 112 and the lower display elements 152 when the expandabledisplay device 200 is disposed in the first display position aredepicted in a partial elevation view taken along sectional line 2B-2B. Aspacer 230 positioned between the upper layer 110 and the lower layer150 maintains a separation distance 232 between the upper layer 110 andthe lower layer 150. With the addition of the spacer 230, the expandabledisplay device 200 has an overall thickness 234. As depicted in FIG. 2B,when the expandable display device 200 is disposed in the first displayposition, the lower display elements 152 are at least partially obscuredby the upper display elements 112. In embodiments, the spacer 230permits the free displacement of the upper layer 110 and the lower layer150. The spacer 230 may maintain a separation distance 232 of less than:about 1 millimeter (mm); about 2 mm; about 3 mm; about 5 mm; or about 10mm. In embodiments, the spacer 230 causes an overall expandable displaydevice thickness of less than: about 3 millimeters (mm); about 7 mm;about 10 mm; or about 15 mm.

The detail 206B in FIG. 2B provides an elevation view of an illustrativedisplay element. Although the detail depicts an elevation of a displayelement 112 included in the upper layer 110, such construction may alsoapply to the display elements 152 included in the lower layer 150. Eachof the upper display elements 112 and/or the lower display elements 152may include an encapsulant material 240 disposed in, on, about, oracross all or a portion of a pixel layer 250 that is disposed in, on,about, or across all or a portion of a circuitry layer 260 that controlsthe function and/or operation of the pixels included in the pixel layer250. The upper display elements 112 are disposed in, on, about, oracross all or a portion of the surface of the expandable substrate 120.The lower display elements 152 are disposed in, on, about, or across allor a portion of the surface of the expandable substrate 160. Althoughnot depicted in detail 206B, in some implementations, some or all of theupper display elements 112 and/or some or all of the lower displayelements 152 may include an electromagnetic output layer disposedbetween the pixel layer 250 and the circuitry layer 260. When present,such an electromagnetic output layer provides narrow spectrum or broadspectrum electromagnetic output, at least a portion of which passesthrough the pixel layer 250, providing a display image to a user viewingthe expandable display device 200.

The encapsulant 240 is an optically translucent or transparent materialthat protects the display elements from damage. The pixel layer 250 mayinclude any currently available or future developed illuminationtechnology, such as: light emitting diodes (LEDs); organic lightemitting diodes (OLEDs); polymer light emitting diodes (PLEDs); quantumdots; or similar. In embodiments, the pixels included in the pixel layer250 may include a plurality of narrow spectrum sources (e.g., redpixels, green pixels, and blue pixels) arranged in a defined pattern,such as a Bayer filter pattern. In embodiments, the pixels included inthe pixel layer 250 may include one or more broad spectrum sources(e.g., white light source) and the pixel layer may include a colorfilter layer. The circuitry layer 260 in the upper display elements 112is conductively coupled to the flexible connectors 140 and providespower and control signals from the expandable display control circuitry102 to each of the pixels included in each upper display element 152.The circuitry layer 260 in the lower display elements 152 isconductively coupled to the flexible connectors 180 and provides powerand control signals from the expandable display control circuitry 102 toeach of the pixels included in each upper display element 152. Inembodiments, the circuitry layer 260 may include any number and/orcombination of currently available and/or future developed electroniccomponents, semiconductor devices, and/or logic elements. Examplecomponents that may be found in the circuitry layer 260 include but arenot limited to: amorphous silicon thin film transistors (a-Si TFTs);polycrystalline TFTs (pc-Si TFTs), organic TFTs (OTFTs), embeddedpassive components and the like.

Turning next to FIG. 2C, the expanded display device 200 is depicted inthe second display position in which the second display area has anincreased width 270 and an increased height 280. The spacing between theupper display elements 112 has increased from the first gap 130 spacing132A to a second gap 130 spacing 132B that exposes at least a portion ofthe lower display elements 152. In embodiments, when in the seconddisplay position, the expandable display device 200 may have an extendedwidth 270 that is greater than: about 1.25×; about 1.5×; about 1.75×; orabout 2.0× the width 210 when the expandable display device is disposedin the first display position. In embodiments, when in the extendedsecond display position, the expandable display device 200 may have anextended height 280 that is greater than: about 1.25×; about 1.5×; about1.75×; or about 2.0× the height 220 when the expandable display device200 is disposed in the first display position.

Turning to FIG. 2D, the relative positions of the upper display elements112 and the lower display elements 152 when the expandable displaydevice 200 is disposed in the second display position are depicted in apartial elevation view. As depicted in FIG. 2D, emissions 290 from boththe upper display elements 112 and the lower display elements 152 arenow visible. The spacing 132B of gaps 130 separating the upper displayelements 112 included in the upper display layer 110 has increased overthe spacing 132A when the expandable display device 200 is disposed inthe first display position. Similarly, the spacing 172B of gaps 170separating the lower display elements 152 included in the lower displaylayer 150 has increased over the spacing 172A when the expandabledisplay device 200 is disposed in the first display position. Inembodiments, when in the extended second display position, the gapspacing 132B separating the upper display elements 112 included in theupper display layer 110 may be greater than: about 1.25×; about 1.5×;about 1.75×; or about 2.0× of the gap spacing 132A when the expandabledisplay device 200 is disposed in the first display position. Inembodiments, when in the extended second display position, the gapspacing 172B separating the lower display elements 152 included in thelower display layer 150 may be greater than: about 1.25×; about 1.5×;about 1.75×; or about 2.0× of the gap spacing 152A when the expandabledisplay device 200 is disposed in the first display position.

FIG. 3A is a cross-sectional elevation of another illustrative upperdisplay element 300A that includes a rigid substrate 310, in accordancewith at least one embodiment described herein. FIG. 3B is across-sectional elevation of another illustrative lower display element300B that includes a rigid substrate 300B, in accordance with at leastone embodiment described herein. As depicted in FIG. 3A, in embodiments,the upper display element 300A may be separately fabricated on a rigidsubstrate layer 310 which is then bonded to otherwise affixed to thesurface of the expandable substrate 120. As depicted in FIG. 3B, inembodiments, the lower display element 300B may be separately fabricatedon a rigid substrate layer 310 which is then bonded to otherwise affixedto the surface of the expandable substrate 160. The rigid substratelayer 310 may include any rigid dielectric material capable of beingbonded to an underlying expandable substrate.

In embodiments, the upper display element 300A and/or the lower displayelement may include one or more illumination layers 320 that generateand emit either a narrow spectrum electromagnetic energy (e.g.,electromagnetic radiation emissions in the blue or ultraviolet spectrum)or broad spectrum electromagnetic energy (e.g., electromagneticradiation emission across all or a portion of the visibleelectromagnetic spectrum). In embodiments, the one or more illuminationlayers 320 may be used on conjunction with a quantum dot pixel layer250. In such embodiments, the circuitry layer 260 may provide powerand/or control signaling to the illumination layer 320.

FIG. 4 is a plan view of an illustrative system 400 that includes twodisplay elements 410A and 410B conductively coupled using a flexibleinterconnect 420, in accordance with at least one embodiment describedherein. The display elements 410A and 410B may represent either or bothupper display elements 112 and/or lower display elements 152. Theflexible interconnect 420 may represent either or both upper flexibleinterconnects 140 and/or lower flexible interconnects 180.

The flexible interconnect 420 includes one or more conductive traces 430disposed within a flexible dielectric material 440. In embodiments, anexample flexible dielectric material 440 may include one or morepolyimides. The flexible interconnect 420 may have any shape or physicalgeometry capable of accommodating the movement of the display elements410 from the first display position to the second display position.Example shapes or physical geometries suitable for use as a flexibleinterconnect 420 may include but are not limited to: spring-likestructures; dog-bone like structures; or three-dimensional bucklestructures.

FIG. 5 is a schematic diagram of an illustrative electronic,processor-based, device 500 that includes processor circuitry 510 and agraphics processing unit 512 coupled to an expandable display devicesuch as described in detail with regard to FIGS. 1-4, in accordance withat least one embodiment described herein. The processor-based device 500may additionally include one or more of the following: a wirelessinput/output (I/O) interface 520, a wired I/O interface 530, systemmemory 540, power management circuitry 550, a network interface 570, anda non-transitory storage device 590. The following discussion provides abrief, general description of the components forming the illustrativeprocessor-based device 500. Example, non-limiting processor-baseddevices 500 may include, but are not limited to: smartphones, wearablecomputers, portable computing devices, handheld computing devices,desktop computing devices, blade server devices, workstations, andsimilar.

The processor circuitry 510 may include any number, type, or combinationof currently available or future developed devices capable of executingmachine-readable instruction sets. The processor circuitry 510 mayinclude but is not limited to any current or future developed single- ormulti-core processor or microprocessor, such as: on or more systems on achip (SOCs); central processing units (CPUs); digital signal processors(DSPs); graphics processing units (GPUs); application-specificintegrated circuits (ASICs), programmable logic units, fieldprogrammable gate arrays (FPGAs), and the like. Unless describedotherwise, the construction and operation of the various blocks shown inFIG. 5 are of conventional design. Consequently, such blocks need not bedescribed in further detail herein, as they will be understood by thoseskilled in the relevant art. A bus 516 interconnects at least some ofthe components of the processor-based device 500 and may employ anycurrently available or future developed serial or parallel busstructures or architectures.

In embodiments, the processor-based device 500 includes graphicsprocessor circuitry 512 capable of executing machine-readableinstruction sets 514 and generating an output signal capable ofproviding a display output to the LCD display device 100. Those skilledin the relevant art will appreciate that the illustrated embodiments aswell as other embodiments may be practiced with other processor-baseddevice configurations, including portable electronic or handheldelectronic devices, for instance smartphones, portable computers,wearable computers, consumer electronics, personal computers (“PCs”),network PCs, minicomputers, server blades, mainframe computers, and thelike. The processor circuitry 510 may include any number of hardwired orconfigurable circuits, some or all of which may include programmableand/or configurable combinations of electronic components, semiconductordevices, and/or logic elements that are disposed partially or wholly ina PC, server, or other computing system capable of executingmachine-readable instructions.

The processor-based device 500 includes a bus or similar communicationslink 516 that communicably couples and facilitates the exchange ofinformation and/or data between various system components including theprocessor circuitry 510, the graphics processor circuitry 512, one ormore wireless I/O interfaces 520, one or more wired I/O interfaces 530,the system memory 540, one or more network interfaces 570, and/or one ormore storage devices 590. The processor-based device 500 may be referredto in the singular herein, but this is not intended to limit theembodiments to a single processor-based device 500, since in certainembodiments, there may be more than one processor-based device 500 thatincorporates, includes, or contains any number of communicably coupled,collocated, or remote networked circuits or devices.

The system memory 540 may include read-only memory (“ROM”) 542 andrandom access memory (“RAM”) 546. A portion of the ROM 542 may be usedto store or otherwise retain a basic input/output system (“BIOS”) 544.The BIOS 544 provides basic functionality to the processor-based device500, for example by causing the processor circuitry 510 to load and/orexecute one or more machine-readable instruction sets 514. Inembodiments, at least some of the one or more machine-readableinstruction sets 514 cause at least a portion of the processor circuitry510 to provide, create, produce, transition, and/or function as adedicated, specific, and particular machine, for example a wordprocessing machine, a digital image acquisition machine, a media playingmachine, a gaming system, a communications device, a smartphone, orsimilar.

The processor-based device 500 may include at least one wirelessinput/output (I/O) interface 520. The at least one wireless I/Ointerface 520 may be communicably coupled to one or more physical outputdevices 522 (tactile devices, video displays, audio output devices,hardcopy output devices, etc.). The at least one wireless I/O interface520 may communicably couple to one or more physical input devices 524(pointing devices, touchscreens, keyboards, tactile devices, etc.). Theat least one wireless I/O interface 520 may include any currentlyavailable or future developed wireless I/O interface. Example wirelessI/O interfaces include, but are not limited to: BLUETOOTH®, near fieldcommunication (NFC), and similar.

The processor-based device 500 may include one or more wiredinput/output (I/O) interfaces 530. The at least one wired I/O interface530 may be communicably coupled to one or more physical output devices522 (tactile devices, video displays, audio output devices, hardcopyoutput devices, etc.). The at least one wired I/O interface 530 may becommunicably coupled to one or more physical input devices 524 (pointingdevices, touchscreens, keyboards, tactile devices, etc.). The wired I/Ointerface 530 may include any currently available or future developedI/O interface. Example wired I/O interfaces include, but are not limitedto: universal serial bus (USB), IEEE 1394 (“FireWire”), and similar.

The processor-based device 500 may include one or more communicablycoupled, non-transitory, data storage devices 590. The data storagedevices 590 may include one or more hard disk drives (HDDs) and/or oneor more solid-state storage devices (SSDs). The one or more data storagedevices 590 may include any current or future developed storageappliances, network storage devices, and/or systems. Non-limitingexamples of such data storage devices 590 may include, but are notlimited to, any current or future developed non-transitory storageappliances or devices, such as one or more magnetic storage devices, oneor more optical storage devices, one or more electro-resistive storagedevices, one or more molecular storage devices, one or more quantumstorage devices, or various combinations thereof. In someimplementations, the one or more data storage devices 590 may includeone or more removable storage devices, such as one or more flash drives,flash memories, flash storage units, or similar appliances or devicescapable of communicable coupling to and decoupling from theprocessor-based device 500.

The one or more data storage devices 590 may include interfaces orcontrollers (not shown) communicatively coupling the respective storagedevice or system to the bus 516. The one or more data storage devices590 may store, retain, or otherwise contain machine-readable instructionsets, data structures, program modules, data stores, databases, logicalstructures, and/or other data useful to the processor circuitry 510and/or graphics processor circuitry 512 and/or one or more applicationsexecuted on or by the processor circuitry 510 and/or graphics processorcircuitry 512. In some instances, one or more data storage devices 590may be communicably coupled to the processor circuitry 510, for examplevia the bus 516 or via one or more wired communications interfaces 530(e.g., Universal Serial Bus or USB); one or more wireless communicationsinterfaces 520 (e.g., Bluetooth®, Near Field Communication or NFC);and/or one or more network interfaces 570 (IEEE 802.3 or Ethernet, IEEE802.11, or WiFi®, etc.).

Machine-readable instruction sets 514 and other programs, applications,logic sets, and/or modules may be stored in whole or in part in thesystem memory 540. Such instruction sets 514 may be transferred, inwhole or in part, from the one or more data storage devices 590. Theinstruction sets 514 may be loaded, stored, or otherwise retained insystem memory 540, in whole or in part, during execution by theprocessor circuitry 510 and/or graphics processor circuitry 512.

The processor-based device 500 may include power management circuitry550 that controls one or more operational aspects of the energy storagedevice 552. In embodiments, the energy storage device 552 may includeone or more primary (i.e., non-rechargeable) or secondary (i.e.,rechargeable) batteries or similar energy storage devices. Inembodiments, the energy storage device 552 may include one or moresupercapacitors or ultracapacitors. In embodiments, the power managementcircuitry 550 may alter, adjust, or control the flow of energy from anexternal power source 554 to the energy storage device 552 and/or to theprocessor-based device 500. The power source 554 may include, but is notlimited to, a solar power system, a commercial electric grid, a portablegenerator, an external energy storage device, or any combinationthereof.

For convenience, the processor circuitry 510, the graphics processorcircuitry 512, the wireless I/O interface 520, the wired I/O interface530, the system memory 540, the power management circuitry 550, thenetwork interface 570, and the storage device 590 are illustrated ascommunicatively coupled to each other via the bus 516, thereby providingconnectivity between the above-described components. In alternativeembodiments, the above-described components may be communicativelycoupled in a different manner than illustrated in FIG. 5. For example,one or more of the above-described components may be directly coupled toother components, or may be coupled to each other, via one or moreintermediary components (not shown). In another example, one or more ofthe above-described components may be integrated into the processorcircuitry 510 and/or the graphics processor circuitry 512. In someembodiments, all or a portion of the bus 516 may be omitted and thecomponents are coupled directly to each other using suitable wired orwireless connections.

FIG. 6 is a plan view of an illustrative expandable display system 600that includes an upper display layer 110 and a lower display layer 150that are shown separated, in accordance with at least one embodimentdescribed herein. The expandable display system 600 is depicted in thesecond display position in which each of the plurality of lower displayelements 152A-152 n included in the lower display layer 150 are visiblethrough gaps or voids 132B that exist between each of the plurality ofupper display elements 112A-112 n included in the upper display layer110.

FIGS. 7A through 7G depict an illustrative method 700 for manufacturingor producing an illustrative expandable display device such as depictedand described in FIGS. 1-6, in accordance with at least one embodimentdescribed herein. As used in FIGS. 7A through 7G, the display element710 may represent either or both an upper display element 112 and/or alower display element 152.

FIG. 7A is an elevation depicting the detachable attachment ordetachable affixing of an illustrative upper surface of a displayelement 710 to an illustrative first rigid carrier member 720, inaccordance with at least one embodiment described herein. Although FIG.7A depicts only a single display element, the method 700 may be extendedto cover any number of upper display elements 112A-112 n and any numberof lower display elements 152A-152 n. In embodiments, the first rigidcarrier member 720 may include any planar member having dimensions atleast equal to the dimensions of the expandable display device whendisposed in the second display position.

FIG. 7B is an elevation depicting the deposition of an adhesive 730 on,about, or across all or a portion of the lower surface of the displayelement 710, in accordance with at least one embodiment describedherein. In embodiments, the adhesive 730 may include one or moreadhesive films. In other embodiments, the adhesive 730 may include oneor more thermally, chemically, or photochemically activated materials.

FIG. 7C is an elevation depicting the detachable attachment ordetachable affixing of a pre-strained (i.e., extended or displaced tothe second display position) expandable substrate 740 to an illustrativesecond rigid carrier member 750. As used in FIGS. 7C through 7G, theexpandable substrate 740 may represent either or both the upper layerexpandable substrate 120 and/or the lower layer expandable substrate160. The expandable substrate 740 may include one or more elastomeric orpolymeric materials having dielectric properties.

FIG. 7D is an elevation depicting the attachment or affixing of the backside of the display element 710 to the pre-strained (i.e., extended ordisplaced to the second display position) expandable substrate 740. Asdepicted in FIG. 7D, after affixing the back side of the display element710 to the pre-strained expandable substrate 740, the rigid supportmember 720 is detached from the upper surface of the display element710. The resultant structure includes the display element 710 affixed tothe pre-strained expandable substrate 740 by the adhesive 730. Thepre-strained expandable substrate 740 is detachably attached to thesecond rigid carrier member 750.

FIG. 7E is a plan view of an illustrative upper layer 110 that includesa plurality of display elements 710 disposed across all or a portion ofthe pre-strained expandable substrate 740 and an illustrative lowerlayer 150 that includes a plurality of display elements 710 disposedacross all or a portion of the pre-strained expandable substrate 740, inaccordance with at least one embodiment described herein. As depicted inFIG. 7E, the pre-strained expandable substrate may be removed from theareas between the display elements 710.

FIG. 7F is an elevation depicting an expandable display device havingthe upper layer 110 stacked on the lower layer 150 and separated byspacer member 230, in accordance with at least one embodiment describedherein. As depicted in FIG. 7F, the expandable substrate 740 remains ina pre-strained state and the expandable display device is maintained inthe second display position having width 270.

FIG. 7G is an elevation depicting the expandable display device in whichthe expandable substrate 740 has been released and the expandabledisplay device returns to the first display position having width 210.

FIG. 8 is a high-level flow diagram depicting an illustrative expandabledisplay device manufacturing method 800, in accordance with at least oneembodiment described herein. It should be noted that the method definedby 802 through 810 is performed once for the upper layer 110 and oncefor the lower layer 150.

At 802, each of the plurality of display elements is detachably attachedto a rigid support member. In embodiments, an upper surface of each ofthe plurality of display elements may be detachably attached to therigid support member in the locations each of the respective pluralityof display elements will occupy when the expandable display device isdisposed in the second display position.

At 804, an adhesive is patterned, deposited, applied, or otherwisedisposed across all or a portion of the exposed lower surfaces of eachof the plurality of display elements. In embodiments, the adhesive maybe deposited, applied, or otherwise disposed across all or a portion ofthe exposed lower surfaces of each of the plurality of display elementsusing any currently available or future developed material depositionprocesses or methods.

At 806, an expandable substrate is pre-strained by displacing orotherwise stretching the expandable substrate from the first displayposition to the second display position. The pre-strained expandablesubstrate is maintained in the pre-strained state by anchoring theexpandable substrate to a rigid carrier member. In some embodiments, thesurface of the pre-strained expandable substrate may be chemically,photochemically, or thermally activated in preparation for bonding tothe plurality of display elements.

At 808, the adhesive disposed across the back of each of the pluralityof display elements is physically and/or chemically bonded to theactivated surface of the pre-strained expandable substrate.

At 810, portions of the pre-strained expandable substrate between someor all of the plurality of display elements may be physically orchemically removed using any currently available or future developedmaterial removal process or method. In embodiments, the portions of thepre-strained expandable substrate between some or all of the pluralityof display elements is removed by cutting, pressing, or physicalabrasion. The method of 802 through 810 is performed once to create theupper display layer 110 and once to create the lower display layer 150.

At 812, while the upper display layer substrate and the lower displaylayer substrate remain in a pre-strained state, the upper display layer110 is stacked on the lower display layer 150 to produce the expandabledisplay device. In embodiments, spacers 230 may be disposed between theupper display layer 110 and the lower display layer 150. In embodimentsthe spacers 230 may physically couple the upper display layer 110 to thelower display layer 150.

At 814, the pre-strained upper display layer substrate and the lowerdisplay layer substrate are released allowing the upper display layer110 and the lower display layer 150 to return to the unstrained firstdisplay state.

FIG. 9 is a high level logic flow diagram of an illustrative method 900for providing a display image on an expandable display device such asdescribed above in FIGS. 1 through 6 while maintaining a fixed pixeldensity in the display image, in accordance with at least one embodimentdescribed herein. The expandable display device includes an upperdisplay layer 110 that includes a plurality of upper display elements112, each having a defined pixel density and a lower display layer 150that includes a plurality of lower display elements 152, each having thedefined pixel density. The expandable display device 100 may bereversibly, continuously displaced between a first display position thatincludes a relatively small first display area and a second displayposition that includes a relatively large second display area. The pixeldensity of the display image beneficially remains constant at thedefined pixel density at the first display position, the second displayposition, and all points between the first display position and thesecond display position. The method 900 commences at 902.

At 904, the expandable display control circuitry 102 receives one ormore signals 106 from one or more sensors 104. The one or more signals106 include information and/or data associated with the relativeposition of the upper layer 110 with respect to the lower layer 150.

At 906, the expandable display control circuitry 102 determines thevisible portion of each of the upper display elements 112 included inthe upper display layer 110 (e.g., 100% of the upper display elementsare visible to a user) and the visible portion of each of the lowerdisplay elements 152 included in the lower display layer 150. Thevisible portion of each of the lower display elements 152 varies fromabout 0% when the expandable display device 100 is in the first displayposition up to about 100% when the expandable display device 100 is inthe second display position. If the expandable display device 100 is inthe first display position, the one or more signals 106 will includeinformation used by the expandable display control circuitry 102 todetermine that the upper display elements 112 completely obscure thelower display elements 152. In another example, if the upper displaylayer 110 is positioned halfway between the first display position andthe second display position, the one or more signals 106 will includeinformation used by the expandable display control circuitry 102 todetermine the upper display elements 112 and about one half of each ofthe lower display elements 152 are exposed. In yet another example, ifthe upper display layer 110 is positioned in the second displayposition, the one or more signals 106 will include information used bythe expandable display control circuitry 102 to determine the upperdisplay elements 112 and the lower display elements 152 are exposed.

At 908, the expandable display control circuitry 102 apportions adisplay image between the upper display elements 112 and the visibleportion of the lower display elements 152. The expandable displaycontrol circuitry 102 determines a first portion of the display imagefor display and/or presentation via the upper display elements 112.

At 910, the expandable display control circuitry 102 determines a secondportion of the display image for display and/or presentation via thevisible portions of each of the lower display elements 152. The method900 concludes at 912.

While FIGS. 7, 8, and 9 illustrate various operations according to oneor more embodiments, it is to be understood that not all of theoperations depicted in FIGS. 7, 8, and 9 are necessary for otherembodiments. Indeed, it is fully contemplated herein that in otherembodiments of the present disclosure, the operations depicted in FIGS.7, 8, and 9 and/or other operations described herein, may be combined ina manner not specifically shown in any of the drawings, but still fullyconsistent with the present disclosure. Thus, claims directed tofeatures and/or operations that are not exactly shown in one drawing aredeemed within the scope and content of the present disclosure.

As used in this application and in the claims, a list of items joined bythe term “and/or” can mean any combination of the listed items. Forexample, the phrase “A, B and/or C” can mean A; B; C; A and B; A and C;B and C; or A, B and C. As used in this application and in the claims, alist of items joined by the term “at least one of” can mean anycombination of the listed terms. For example, the phrases “at least oneof A, B or C” can mean A; B; C; A and B; A and C; B and C; or A, B andC.

As used in any embodiment herein, the terms “system” or “module” mayrefer to, for example, software, firmware and/or circuitry configured toperform any of the aforementioned operations. Software may be embodiedas a software package, code, instructions, instruction sets and/or datarecorded on non-transitory computer readable storage mediums. Firmwaremay be embodied as code, instructions or instruction sets and/or datathat are hard-coded (e.g., nonvolatile) in memory devices.

As used in any embodiment herein, the term “circuitry” may comprise, forexample, singly or in any combination, hardwired circuitry, programmablecircuitry such as computer processors comprising one or more individualinstruction processing cores, state machine circuitry, and/or firmwarethat stores instructions executed by programmable circuitry or futurecomputing paradigms including, for example, massive parallelism, analogor quantum computing, hardware embodiments of accelerators such asneural net processors and non-silicon implementations of the above. Thecircuitry may, collectively or individually, be embodied as circuitrythat forms part of a larger system, for example, an integrated circuit(IC), system on-chip (SoC), desktop computers, laptop computers, tabletcomputers, servers, smartphones, etc.

Any of the operations described herein may be implemented in a systemthat includes one or more mediums (e.g., non-transitory storage mediums)having stored therein, individually or in combination, instructions thatwhen executed by one or more processors perform the methods. Here, theprocessor may include, for example, a server CPU, a mobile device CPU,and/or other programmable circuitry. Also, it is intended thatoperations described herein may be distributed across a plurality ofphysical devices, such as processing structures at more than onedifferent physical location. The storage medium may include any type oftangible medium, for example, any type of disk including hard disks,floppy disks, optical disks, compact disk read-only memories (CD-ROMs),compact disk rewritables (CD-RWs), and magneto-optical disks,semiconductor devices such as read-only memories (ROMs), random accessmemories (RAMs) such as dynamic and static RAMs, erasable programmableread-only memories (EPROMs), electrically erasable programmableread-only memories (EEPROMs), flash memories, Solid State Disks (SSDs),embedded multimedia cards (eMMCs), secure digital input/output (SDIO)cards, magnetic or optical cards, or any type of media suitable forstoring electronic instructions. Other embodiments may be implemented assoftware executed by a programmable control device.

Thus, the present disclosure is directed to systems and methods offorming an expandable display device capable of maintaining a fixedpixel density at any display area from a relatively smaller firstdisplay area to a relatively larger second display area. The expandabledisplay device includes an upper display layer and a lower displaylayer. In a first display position, the display elements having adefined pixel density included in the upper display layer obscure thedisplay elements having the defined pixel density included in the lowerdisplay layer. The upper display layer and lower display layers aredisposed on respective expandable substrates capable of continuous,reversible, displacement between the first display position and thesecond display position. In the second display position, the displayelements included in the lower display layer are visible through gaps,voids, or apertures formed between the display elements included in theupper display layer. The resultant display provides a uniform pixeldensity at all displacements from the first display position to thesecond display position.

The following examples pertain to further embodiments. The followingexamples of the present disclosure may comprise subject material such asat least one device, a method, at least one machine-readable medium forstoring instructions that when executed cause a machine to perform actsbased on the method, means for providing an expandable display devicethat includes an expandable upper display layer containing a pluralityof display elements and an expandable lower display layer containing aplurality of display elements. The display elements included in theupper display layer and the display elements included in the lowerdisplay layer have similar or identical pixel densities. The resultantexpandable display device advantageously provides the same pixel densityat all displacements from the first, relatively smaller area, displayposition through the second, relatively larger display area.

According to example 1, there is provided a variable viewing areadisplay device continuously displaceable between a first displayposition that provides a first display area and a second displayposition that provides a second display area, the second display arealarger than the first display area. The display device may include: anupper display layer that includes a plurality of upper display elementsdisposed on an expandable substrate, the expandable substratecontinuously displaceable between the first display position and thesecond display position; a lower display layer that includes a pluralityof lower display elements disposed on an expandable substrate, theexpandable substrate continuously displaceable between the first displayposition and the second display position wherein: in the first displayposition the plurality of upper display elements obscure at least aportion of the plurality of lower display elements; as the displaydevice is displaced from the first position to the second position, atleast a portion of each of the plurality of lower display elements arevisible through void spaces formed in the expandable substrate of theupper display layer between each of at least some of the plurality ofupper display elements; and in the second position each of the pluralityof lower display elements are visible through the void spaces formed inthe expandable substrate of the upper display layer between each of atleast some of the plurality of upper display elements.

Example 2 may include elements of example 1 and the expandable displaydevice includes: a plurality of upper flexible interconnects, each ofthe plurality of upper flexible interconnects conductively coupling eachof the plurality of upper display elements to at least one other of theupper display elements included in the plurality of upper displayelements; and a plurality of lower flexible interconnects, each of theplurality of lower flexible interconnects conductively coupling each ofthe plurality of upper display elements to at least one other of thelower display elements included in the plurality of upper displayelements.

Example 3 may include elements of any of examples 1 or 2 where each ofthe first plurality of flexible interconnects comprises at least oneconductive layer disposed at least partially surrounded by a flexibledielectric material; and where at least a portion of the flexibleinterconnects included in the first plurality of flexible interconnectsare biased toward the first display position.

Example 4 may include elements of any of examples 1 through 3 where eachof the second plurality of flexible interconnects comprises at least oneconductive layer at least partially surrounded by a flexible dielectricmaterial; and where at least a portion of the flexible interconnectsincluded in the second plurality of flexible interconnects are biasedtoward the first display position.

Example 5 may include elements of any of examples 1 through 4 where, inthe first display position, the upper display elements are separatedfrom at least one other of the upper display elements by a firstdistance of less than about 2 millimeters (mm).

Example 6 may include elements of any of examples 1 through 5 where, inthe first display position, the lower display elements are separatedfrom at least one other of the lower display elements by a firstdistance of less than about 2 millimeters (mm).

Example 7 may include elements of any of examples 1 through 6 where eachof the upper display elements included in the plurality of upper displayelements may include: a flexible support layer; a pixel circuit layerdisposed physically proximate to the flexible support layer; a lightemitting layer conductively coupled to and disposed physically proximatethe pixel circuit layer; and a flexible encapsulant disposed physicallyproximate the light emitting layer.

Example 8 may include elements of any of examples 1 through 7 where eachof the lower display elements included in the plurality of lower displayelements may include: a support layer; a pixel circuit layer disposedphysically proximate to the flexible support layer; a light emittinglayer conductively coupled to and disposed physically proximate thepixel circuit layer; and a flexible encapsulant disposed physicallyproximate the light emitting layer.

Example 9 may include elements of any of examples 1 through 8 where thelight emitting layer may include at least one of: a plurality of lightemitting diodes; a plurality of polymer light emitting diodes (PLEDs);or a plurality of organic light emitting diodes (OLEDs).

Example 10 may include elements of any of examples 1 through 9 whereeach of the upper display elements included in the plurality of upperdisplay elements may include a first pixel matrix; and where each of thelower display elements included in the plurality of lower displayelements comprises a second pixel matrix.

Example 11 may include elements of any of examples 1 through 10 wherethe first pixel matrix comprises an “n₁×m₁” rectangular pixel matrix;and where the second pixel matrix comprises an “n₂×m₂” rectangular pixelmatrix.

Example 12 may include elements of any of examples 1 through 11 wherethe “n₁×m₁” rectangular pixel matrix has the same pixel row and columncount as the “n₂×m₂” rectangular pixel matrix.

Example 13 may include elements of any of examples 1 through 12 and theexpandable display device includes: sensor circuitry to determine adisplacement from the first display position; expandable display controlcircuitry coupled to the sensor circuitry; a storage device thatincludes machine-executable instructions that, when executed by theexpandable display control circuitry, cause the expandable displaycontrol circuitry to: deactivate pixels on at least a portion of thelower display elements when the upper display layer is in the firstdisplay position; and progressively activate the pixels on exposedportions of at least a portion of the lower display elements as theupper display layer transitions from the first display position to thesecond display position.

Example 14 may include elements of any of examples 1 through 13 wherethe sensor circuitry may include at least one of: strain gaugecircuitry; stretch sensing circuitry; proximity sensing circuitry;ultrasonic displacement sensing circuitry; or laser displacement sensingcircuitry.

Example 15 may include elements of any of examples 1 through 14 wherethe variable viewing area display device may include a display devicecontinuously displaceable along a first axis.

Example 16 may include elements of any of examples 1 through 15 wherethe variable viewing area display device comprises a display devicecontinuously displaceable along a first axis and a second axis, thefirst axis orthogonal to the second axis.

Example 17 may include elements of any of examples 1 through 16 wherethe upper display elements comprise display elements having a firstpixel density; and where the lower display elements comprise displayelements having a second pixel density, the second pixel density equalto or greater than the first pixel density.

Example 18 may include elements of any of examples 1 through 17 where,in the first display position, the variable viewing area display deviceprovides an image with a first pixel density; and where in the seconddisplay position, the variable viewing area display device provides animage with at least the first pixel density.

According to example 19, there is provided a variable area displaymethod. The method may include: receiving, by expandable display controlcircuitry, a signal that includes information indicative of a relativeposition of an upper display layer with respect to a lower displaylayer; identifying, by the expandable display control circuitry, anexposed portion of each of a plurality of lower display elements basedon the relative position of the upper display layer with respect to thelower display layer; determining, by the expandable display controlcircuitry, a first portion of a display image for display using aplurality of upper display elements included in the upper display layer;and determining, by the expandable display control circuitry, a secondportion of a display image for display using the identified exposedportion of each of the lower display elements such that a display imagehaving a uniform pixel density is maintained.

Example 20 may include elements of example 19 where receiving the signalthat includes the information indicative of the relative position of theupper display layer with respect to the lower display layer may include:receiving, by the expandable display control circuitry, the signal thatincludes the information indicative of the relative position, along asingle axis, of the upper display layer with respect to the lowerdisplay layer.

Example 21 may include elements of any of examples 19 or 20 wherereceiving the signal that includes the information indicative of therelative position of the upper display layer with respect to the lowerdisplay layer may include: receiving, by the expandable display controlcircuitry, the signal that includes the information indicative of therelative position, along each of two orthogonal axes, of the upperdisplay layer with respect to the lower display layer.

Example 22 may include elements of any of examples 19 through 21, andthe method may additionally include: generating, by one or more sensors,the signal that includes information indicative of the relative positionof the upper display layer with respect to the lower display layer.

Example 23 may include elements of any of examples 19 through 22 wheregenerating the signal that includes information indicative of therelative position of the upper display layer with respect to the lowerdisplay layer may include: generating the signal that includesinformation indicative of the relative position of the upper displaylayer with respect to the lower display layer using at least one of:strain gauge circuitry; stretch sensing circuitry; proximity sensingcircuitry; ultrasonic displacement sensing circuitry; or laserdisplacement sensing circuitry.

According to example 24, there is provided a variable area displaymethod. The method may include: pre-straining an upper expandablesubstrate having an upper surface and a lower expandable substratehaving an upper surface; affixing a rear surface of each of a pluralityof upper display elements to the upper surface of the upper expandablesubstrate; each of the plurality of upper display elements spaced apartfrom at least one other of the plurality of upper display elements toform interstitial spaces separating each of the plurality of upperdisplay elements from each other on the upper expandable substrate;affixing a rear surface each of a plurality of lower display elements tothe upper surface of the lower expandable substrate; each of theplurality of lower display elements spaced apart from at least one otherof the plurality of lower display elements to form interstitial spacesseparating each of the plurality of lower display elements from eachother on the lower expandable substrate; removing portions of the upperexpandable substrate in the interstitial spaces that separate theplurality of upper display elements; stacking the pre-strained upperexpandable substrate on the pre-strained lower expandable substrate; andreleasing the strain on the upper expandable substrate and the strain onthe lower expandable substrate.

Example 25 may include elements of example 24 and the method mayadditionally include: detachably attaching each of the plurality ofupper display elements to a first rigid support; and detachablyattaching each of the plurality of lower display elements to a secondrigid support.

Example 26 may include elements of any of examples 24 or 25, and themethod may additionally include: depositing an adhesive across at leasta portion of the rear surface of the plurality of upper displayelements; and depositing an adhesive across at least a portion of therear surface of the plurality of lower display elements.

Example 27 may include elements of any of examples 24 through 26, andthe method may additionally include: activating the upper surface of theupper expandable substrate prior to affixing the rear surface of each ofthe plurality of upper display elements to the upper surface of theupper expandable substrate; and activating the upper surface of thelower expandable substrate prior to affixing the rear surface of each ofthe plurality of lower display elements to the upper surface of thelower expandable substrate.

Example 28 may include elements of any of examples 24 through 27 wherepre-straining the upper expandable substrate may include: pre-strainingat least a portion of an upper expandable substrate that includes atleast one elastomeric material; and where pre-straining the lowerexpandable substrate may include: pre-straining at least a portion of alower expandable substrate that includes at least one elastomericmaterial.

According to example 29, there is provided a variable area displaysystem. The system may include: means for receiving a signal thatincludes information indicative of a relative position of an upperdisplay layer with respect to a lower display layer; means foridentifying an exposed portion of each of a plurality of lower displayelements based on the relative position of the upper display layer withrespect to the lower display layer; means for determining a firstportion of a display image for display using a plurality of upperdisplay elements included in the upper display layer; and means fordetermining a second portion of a display image for display using theidentified exposed portion of each of the lower display elements suchthat a display image having a uniform pixel density is maintained.

Example 30 may include elements of example 29 where the means forreceiving the signal that includes the information indicative of therelative position of the upper display layer with respect to the lowerdisplay layer may include: means for receiving the signal that includesthe information indicative of the relative position, along a singleaxis, of the upper display layer with respect to the lower displaylayer.

Example 31 may include elements of any of examples 29 or 30 where themeans for receiving the signal that includes the information indicativeof the relative position of the upper display layer with respect to thelower display layer may include: means for receiving the signal thatincludes the information indicative of the relative position, along eachof two orthogonal axes, of the upper display layer with respect to thelower display layer.

Example 32 may include elements of any of examples 29 through 31, andthe system may additionally include: means for generating the signalthat includes information indicative of the relative position of theupper display layer with respect to the lower display layer.

According to example 33, there is provided a non-transitorymachine-readable storage medium that includes instructions. Theinstructions, when executed by expandable display control circuitry,cause the expandable display control circuitry to: receive a signal thatincludes information indicative of a relative position of an upperdisplay layer with respect to a lower display layer; identify an exposedportion of each of a plurality of lower display elements based on therelative position of the upper display layer with respect to the lowerdisplay layer; determine a first portion of a display image for displayusing a plurality of upper display elements included in the upperdisplay layer; and determine a second portion of a display image fordisplay using the identified exposed portion of each of the lowerdisplay elements such that a display image having a uniform pixeldensity is maintained.

Example 34 may include elements of example 33 where the instructionsthat cause the expandable display control circuitry to receive a signalthat includes information indicative of a relative position of an upperdisplay layer with respect to a lower display layer further cause theexpandable display control circuitry to: receive the signal thatincludes the information indicative of the relative position, along asingle axis, of the upper display layer with respect to the lowerdisplay layer.

Example 35 may include elements of any of examples 33 or 34 where theinstructions that cause the expandable display control circuitry toreceive a signal that includes information indicative of a relativeposition of an upper display layer with respect to a lower display layerfurther cause the expandable display control circuitry to: receive thesignal that includes the information indicative of the relativeposition, along each of two orthogonal axes, of the upper display layerwith respect to the lower display layer.

According to example 36, there is provided an electronic device. Theelectronic device may include: a printed circuit board; processorcircuitry; input/output (I/O) circuitry; and a variable viewing areadisplay device continuously displaceable between a first displayposition that provides a first display area and a second displayposition that provides a second display area, the second display arealarger than the first display area, the variable viewing area displaydevice comprising: an upper display layer that includes a plurality ofupper display elements disposed on an expandable substrate, theexpandable substrate continuously displaceable between the first displayposition and the second display position; a lower display layer thatincludes a plurality of lower display elements disposed on an expandablesubstrate, the expandable substrate continuously displaceable betweenthe first display position and the second display position wherein: inthe first display position the plurality of upper display elementsobscure at least a portion of the plurality of lower display elements;as the display device is displaced from the first position to the secondposition, at least a portion of each of the plurality of lower displayelements are visible through void spaces formed in the expandablesubstrate of the upper display layer between each of at least some ofthe plurality of upper display elements; and in the second position eachof the plurality of lower display elements are visible through the voidspaces formed in the expandable substrate of the upper display layerbetween each of at least some of the plurality of upper displayelements.

Example 37 may include elements of example 36 and the device mayadditionally include: a plurality of upper flexible interconnects, eachof the plurality of upper flexible interconnects conductively couplingeach of the plurality of upper display elements to at least one other ofthe upper display elements included in the plurality of upper displayelements; and a plurality of lower flexible interconnects, each of theplurality of lower flexible interconnects conductively coupling each ofthe plurality of upper display elements to at least one other of thelower display elements included in the plurality of upper displayelements.

Example 38 may include elements of example 36 and 37 where each of thefirst plurality of flexible interconnects comprises at least oneconductive layer disposed at least partially surrounded by a flexibledielectric material; and where at least a portion of the flexibleinterconnects included in the first plurality of flexible interconnectsare biased toward the first display position.

Example 39 may include elements of any of examples 36 through 38 whereeach of the second plurality of flexible interconnects comprises atleast one conductive layer at least partially surrounded by a flexibledielectric material; and where at least a portion of the flexibleinterconnects included in the second plurality of flexible interconnectsare biased toward the first display position.

Example 40 may include elements of any of examples 36 through 39 where,in the first display position, the upper display elements are separatedfrom at least one other of the upper display elements by a firstdistance of less than about 2 millimeters (mm).

Example 41 may include elements of any of examples 36 through 40 where,in the first display position, the lower display elements are separatedfrom at least one other of the lower display elements by a firstdistance of less than about 2 millimeters (mm).

Example 42 may include elements of any of examples 36 through 41 whereeach of the upper display elements included in the plurality of upperdisplay elements may include: a flexible support layer; a pixel circuitlayer disposed physically proximate to the flexible support layer; alight emitting layer conductively coupled to and disposed physicallyproximate the pixel circuit layer; and a flexible encapsulant disposedphysically proximate the light emitting layer.

Example 43 may include elements of any of examples 36 through 42 whereeach of the lower display elements included in the plurality of lowerdisplay elements may include: a flexible support layer; a pixel circuitlayer disposed physically proximate to the flexible support layer; alight emitting layer conductively coupled to and disposed physicallyproximate the pixel circuit layer; and a flexible encapsulant disposedphysically proximate the light emitting layer.

Example 44 may include elements of any of examples 36 through 43 wherethe light emitting layer comprises at least one of: a plurality of lightemitting diodes; a plurality of polymer light emitting diodes (PLEDs);or a plurality of organic light emitting diodes (OLEDs).

Example 45 may include elements of any of examples 36 through 44 whereeach of the upper display elements included in the plurality of upperdisplay elements comprises a first pixel matrix; and where each of thelower display elements included in the plurality of lower displayelements comprises a second pixel matrix.

Example 46 may include elements of any of examples 36 through 45 wherethe first pixel matrix comprises an “n₁×m₁” rectangular pixel matrix;and where the second pixel matrix comprises an “n₂×m₂” rectangular pixelmatrix.

Example 47 may include elements of any of examples 36 through 46 wherethe “n₁×m₁” rectangular pixel matrix has the same pixel row and columncount as the “n₂×m₂” rectangular pixel matrix.

Example 48 may include elements of any of examples 36 through 47, andthe electronic device may additionally include: sensor circuitry todetermine a displacement from the first display position; expandabledisplay control circuitry coupled to the sensor circuitry; a storagedevice that includes machine-executable instructions that, when executedby the expandable display control circuitry, cause the expandabledisplay control circuitry to: deactivate pixels on at least a portion ofthe lower display elements when the upper display layer is in the firstdisplay position; and progressively activate the pixels on exposedportions of at least a portion of the lower display elements as theupper display layer transitions from the first display position to thesecond display position.

Example 49 may include elements of any of examples 36 through 48 wherethe sensor circuitry includes at least one of: strain gauge circuitry;stretch sensing circuitry; proximity sensing circuitry; ultrasonicdisplacement sensing circuitry; or laser displacement sensing circuitry.

Example 50 may include elements of any of examples 36 through 49 wherethe variable viewing area display device comprises a display devicecontinuously displaceable along a first axis.

Example 51 may include elements of any of examples 36 through 50 wherethe variable viewing area display device comprises a display devicecontinuously displaceable along a first axis and a second axis, thefirst axis orthogonal to the second axis.

Example 52 may include elements of any of examples 36 through 51 wherethe upper display elements comprise display elements having a firstpixel density; and where the lower display elements comprise displayelements having a second pixel density, the second pixel density equalto or greater than the first pixel density.

Example 53 may include elements of any of examples 36 through 52 where,in the first display position, the variable viewing area display deviceprovides an image with a first pixel density; and where, in the seconddisplay position, the variable viewing area display device provides animage with at least the first pixel density.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intention,in the use of such terms and expressions, of excluding any equivalentsof the features shown and described (or portions thereof), and it isrecognized that various modifications are possible within the scope ofthe claims. Accordingly, the claims are intended to cover all suchequivalents. Various features, aspects, and embodiments have beendescribed herein. The features, aspects, and embodiments are susceptibleto combination with one another as well as to variation andmodification, as will be understood by those having skill in the art.The present disclosure should, therefore, be considered to encompasssuch combinations, variations, and modifications.

As described herein, various embodiments may be implemented usinghardware elements, software elements, or any combination thereof.Examples of hardware elements may include processors, microprocessors,circuits, circuit elements (e.g., transistors, resistors, capacitors,inductors, and so forth), integrated circuits, application specificintegrated circuits (ASIC), programmable logic devices (PLD), digitalsignal processors (DSP), field programmable gate array (FPGA), logicgates, registers, semiconductor device, chips, microchips, chip sets,and so forth.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, appearances of the phrases “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments.

What is claimed:
 1. A variable viewing area display device continuouslydisplaceable between a first display position that provides a firstdisplay area and a second display position that provides a seconddisplay area, the second display area larger than the first displayarea, the display device comprising: an upper display layer thatincludes a plurality of upper display elements disposed on an expandablesubstrate, the expandable substrate continuously displaceable betweenthe first display position and the second display position a lowerdisplay layer that includes a plurality of lower display elementsdisposed on an expandable substrate, the expandable substratecontinuously displaceable between the first display position and thesecond display position wherein: in the first display position theplurality of upper display elements obscure at least a portion of theplurality of lower display elements; as the display device is displacedfrom the first position to the second position, at least a portion ofeach of the plurality of lower display elements are visible through voidspaces formed in the expandable substrate of the upper display layerbetween each of at least some of the plurality of upper displayelements; and in the second position each of the plurality of lowerdisplay elements are visible through the void spaces formed in theexpandable substrate of the upper display layer between each of at leastsome of the plurality of upper display elements.
 2. The variable viewingarea display device of claim 1, further comprising: a plurality of upperflexible interconnects, each of the plurality of upper flexibleinterconnects conductively coupling each of the plurality of upperdisplay elements to at least one other of the upper display elementsincluded in the plurality of upper display elements; and a plurality oflower flexible interconnects, each of the plurality of lower flexibleinterconnects conductively coupling each of the plurality of upperdisplay elements to at least one other of the lower display elementsincluded in the plurality of upper display elements.
 3. The variableviewing area display device of claim 1: wherein each of the firstplurality of flexible interconnects comprises at least one conductivelayer disposed at least partially surrounded by a flexible dielectricmaterial; and wherein at least a portion of the flexible interconnectsincluded in the first plurality of flexible interconnects are biasedtoward the first display position.
 4. The variable viewing area displaydevice of claim 3: wherein each of the second plurality of flexibleinterconnects comprises at least one conductive layer at least partiallysurrounded by a flexible dielectric material; and wherein at least aportion of the flexible interconnects included in the second pluralityof flexible interconnects are biased toward the first display position.5. The variable viewing area display device of claim 1: wherein, in thefirst display position, the upper display elements are separated from atleast one other of the upper display elements by a first distance ofless than about 2 millimeters (mm).
 6. The variable viewing area displaydevice of claim 1: wherein, in the first display position, the lowerdisplay elements are separated from at least one other of the lowerdisplay elements by a first distance of less than about 2 millimeters(mm).
 7. The variable viewing area display device of claim 1 whereineach of the upper display elements included in the plurality of upperdisplay elements comprises: a flexible support layer; a pixel circuitlayer disposed physically proximate to the flexible support layer; alight emitting layer conductively coupled to and disposed physicallyproximate the pixel circuit layer; and a flexible encapsulant disposedphysically proximate the light emitting layer.
 8. The variable viewingarea display device of claim 7 wherein each of the lower displayelements included in the plurality of lower display elements comprises:a flexible support layer; a pixel circuit layer disposed physicallyproximate to the flexible support layer; a light emitting layerconductively coupled to and disposed physically proximate the pixelcircuit layer; and a flexible encapsulant disposed physically proximatethe light emitting layer.
 9. The variable viewing area display device ofclaim 7 wherein the light emitting layer comprises at least one of: aplurality of light emitting diodes; a plurality of polymer lightemitting diodes (PLEDs); or a plurality of organic light emitting diodes(OLEDs).
 10. The variable viewing area display device of claim 1:wherein each of the upper display elements included in the plurality ofupper display elements comprises a first pixel matrix; and wherein eachof the lower display elements included in the plurality of lower displayelements comprises a second pixel matrix.
 11. The variable viewing areadisplay device of claim 10: wherein the first pixel matrix comprises an“n₁×m₁” rectangular pixel matrix; and wherein the second pixel matrixcomprises an “n₂×m₂” rectangular pixel matrix.
 12. The variable viewingarea display device of claim 11 wherein the “n₁×m₁” rectangular pixelmatrix has the same pixel row and column count as the “n₂×m₂”rectangular pixel matrix.
 13. The variable viewing area display deviceof claim 10, further comprising: sensor circuitry to determine adisplacement from the first display position; expandable display controlcircuitry coupled to the sensor circuitry; a storage device thatincludes machine-executable instructions that, when executed by theexpandable display control circuitry, cause the expandable displaycontrol circuitry to: deactivate pixels on at least a portion of thelower display elements when the upper display layer is in the firstdisplay position; and progressively activate the pixels on exposedportions of at least a portion of the lower display elements as theupper display layer transitions from the first display position to thesecond display position.
 14. The variable viewing area display device ofclaim 13 wherein the sensor circuitry includes at least one of: straingauge circuitry; stretch sensing circuitry; proximity sensing circuitry;ultrasonic displacement sensing circuitry; or laser displacement sensingcircuitry.
 15. The variable viewing area display device of claim 1wherein the variable viewing area display device comprises a displaydevice continuously displaceable along a first axis.
 16. The variableviewing area display device of claim 1 wherein the variable viewing areadisplay device comprises a display device continuously displaceablealong a first axis and a second axis, the first axis orthogonal to thesecond axis.
 17. The variable viewing area display device of claim 1:wherein the upper display elements comprise display elements having afirst pixel density; and wherein the lower display elements comprisedisplay elements having a second pixel density, the second pixel densityequal to or greater than the first pixel density.
 18. The variableviewing area display device of claim 1: wherein, in the first displayposition, the variable viewing area display device provides an imagewith a first pixel density; and wherein, in the second display position,the variable viewing area display device provides an image with at leastthe first pixel density.
 19. A variable area display method, comprising:receiving, by expandable display control circuitry, a signal thatincludes information indicative of a relative position of an upperdisplay layer with respect to a lower display layer; identifying, by theexpandable display control circuitry, an exposed portion of each of aplurality of lower display elements based on the relative position ofthe upper display layer with respect to the lower display layer;determining, by the expandable display control circuitry, a firstportion of a display image for display using a plurality of upperdisplay elements included in the upper display layer; and determining,by the expandable display control circuitry, a second portion of adisplay image for display using the identified exposed portion of eachof the lower display elements such that a display image having a uniformpixel density is maintained.
 20. The variable area display method ofclaim 19 wherein receiving the signal that includes the informationindicative of the relative position of the upper display layer withrespect to the lower display layer comprises: receiving, by theexpandable display control circuitry, the signal that includes theinformation indicative of the relative position, along a single axis, ofthe upper display layer with respect to the lower display layer.
 21. Thevariable area display method of claim 19 wherein receiving the signalthat includes the information indicative of the relative position of theupper display layer with respect to the lower display layer comprises:receiving, by the expandable display control circuitry, the signal thatincludes the information indicative of the relative position, along eachof two orthogonal axes, of the upper display layer with respect to thelower display layer.
 22. The variable area display method of claim 19,further comprising: generating, by one or more sensors, the signal thatincludes information indicative of the relative position of the upperdisplay layer with respect to the lower display layer.
 23. The variablearea display method of claim 22 wherein generating the signal thatincludes information indicative of the relative position of the upperdisplay layer with respect to the lower display layer comprises:generating the signal that includes information indicative of therelative position of the upper display layer with respect to the lowerdisplay layer using at least one of: strain gauge circuitry; stretchsensing circuitry; proximity sensing circuitry; ultrasonic displacementsensing circuitry; or laser displacement sensing circuitry.
 24. Avariable area display method, comprising: pre-straining an upperexpandable substrate having an upper surface and a lower expandablesubstrate having an upper surface; affixing a rear surface of each of aplurality of upper display elements to the upper surface of the upperexpandable substrate; each of the plurality of upper display elementsspaced apart from at least one other of the plurality of upper displayelements to form interstitial spaces separating each of the plurality ofupper display elements from each other on the upper expandablesubstrate; affixing a rear surface each of a plurality of lower displayelements to the upper surface of the lower expandable substrate; each ofthe plurality of lower display elements spaced apart from at least oneother of the plurality of lower display elements to form interstitialspaces separating each of the plurality of lower display elements fromeach other on the lower expandable substrate; removing portions of theupper expandable substrate in the interstitial spaces that separate theplurality of upper display elements; stacking the pre-strained upperexpandable substrate on the pre-strained lower expandable substrate; andreleasing the strain on the upper expandable substrate and the strain onthe lower expandable substrate.
 25. A variable area display system,comprising: means for receiving a signal that includes informationindicative of a relative position of an upper display layer with respectto a lower display layer; means for identifying an exposed portion ofeach of a plurality of lower display elements based on the relativeposition of the upper display layer with respect to the lower displaylayer; means for determining a first portion of a display image fordisplay using a plurality of upper display elements included in theupper display layer; and means for determining a second portion of adisplay image for display using the identified exposed portion of eachof the lower display elements such that a display image having a uniformpixel density is maintained.